Antimicrobials

Question 1

Beta-lactam antibiotics mechanism

Answer 1

Interferes with synthesis of bacterial cell wall peptidoglycan

(inhibits transpeptidation enzyme which links peptidoglycan chains)

Question 2

Beta-lactam eg

Answer 2

Penicillin
Cephalosporins
Carbapenems

Question 3

Penicillin eg

Answer 3

Co-amoxiclav

Amoxicillin

Question 4

Penicillin use

Answer 4

Wide -> need to narrow down

Bacterial meningitidis 
Bone and joint infections
soft tissue infections
UTI/STI
Pneumonia

Question 5

Cephalosporins eg

Answer 5

Ceftriaxone
Cefuroxime
Cefotaxime

Question 6

Cephalosporins use

Answer 6

Septicaemia

Meningitis

Question 7

Carbapenems structure

Answer 7

Carbon atom instead of sulfur (like penicillin has)

Question 8

Carbapenems use

Answer 8

Penicillin allergy

broad

Question 9

Carbapenems eg

Answer 9

Meropenem
Imipenem
Ertapenem

Question 10

Glycopeptide antibiotics mechanism

Answer 10

Inhibit cell wall synthesis (prevents incorporation of brick subunit)

NAG-NAM-PEP

Question 11

Glycopeptide eg

Answer 11

Vancomycin

Teicoplanin

Question 12

Glycopeptide use

Answer 12

Gram positive
Orally for treatment of C difficile
(not absorbed in GI)

Question 13

Antibacterials affecting bacterial protein synthesis

Answer 13

Tetracyclines
Aminoglycosides
Macrolides
Oxazolidinones
Lincosamides

Question 14

Tetracyclines mechanism

Answer 14

Bind to bacterial ribosome

prevent binding of tRNA

Question 15

Tetracyclines eg

Answer 15

Doxycylcine

Tetracyline

Question 16

Tetracycline use

Answer 16

Respiratory tract infections
Acne
Chlamydia
Lyme disease

Question 17

Tetracyclines important

Answer 17

CANNOT give to children under 12, pregnant or breastfeeding women
Stains teeth

Question 18

Aminoglycosides mechanism

Answer 18

Bind to ribosomes
Misread mRNA
Incorrect amino acids = loss of function

BACTERICIDAL

Question 19

Aminoglycosides example

Answer 19

Gentamicin

Question 20

Aminoglycosides use

Answer 20

Gram negative (septicaemia) mostly

Question 21

Caution aminoglycosides

Answer 21

nephro/ototoxic (kidney/ear toxic)

Strict therapeutic dose

Question 22

Macrolides mechanism

Answer 22

effect ribosome translocation

bactericidal

Question 23

macolides examples

Answer 23

Clarithromycin
Erthromycin
Azithtromycin

Question 24

Macrolides use

Answer 24

similar to penicillin

respiratory pathogens

Question 25

Oxazolidinones example

Answer 25

Linezolid

Question 26

Oxazolidinones use

Answer 26

Broad if other antibiotics fail Gram positive Anaerobe Pneumonia, septicaemia

Question 27

Lincosamides action

Answer 27

effect ribosomal translocation (same as macrolides)

Question 28

Lincosamides eg

Answer 28

Clindamycin

Question 29

Lincosamides use

Answer 29

gram positive cocci penicillin resistant staphylococci anaerobic bacteria

Question 30

Quinolones mechanism

Answer 30

Inhibit topoisomerase 2 (bacterial DNA gyrase)

Question 31

Normal topoisomerase action

Answer 31

usually produces supercoil DNA and permits transcription and replication

Question 32

Quinolones example

Answer 32

Ciprofloxacin | Levofloxacin

Question 33

quinolones use

Answer 33

Gran negative, positive and atypical UTI (complicated) Gonnorrhoea

Question 34

side effects quinolones TAC

Answer 34

``` Tendinitis (rupture?) Aortic dissection (split walls) CNS effects (convulsions) ```

Question 35

Antibacterials that interfere with folate synthesis/action

Answer 35

Sulfonamides | Trimethoprim

Question 36

Sulfonamides mechamism

Answer 36

structural analogue of PABA PABA required synthesis of folate and therefore for DNA/RNA synthesis competes with PABA

Question 37

enzyme sufronamides compete with PABA for

Answer 37

Dihydropteroate synthetase = less folic acid production

Question 38

sulfonamides eg

Answer 38

Sulfamethoxazole | Sulfasalazine

Question 39

Trimethoprim

Answer 39

Folate antagonist | Reversible inhibitor for dihydrofolate reductase

Question 40

why doesnt trimethoprim not destroy host DNA synthesis?

Answer 40

Binds to bacterial enzyme with higher affinity than human

Question 41

Trimethoprim use

Answer 41

UTI (careful for reproductive age - neural tube defects)

Question 42

Metronidazole use

Answer 42

Antiprotozoal | Anaerobic bacteria

Question 43

Metronidazole effects

Answer 43

Disulfiram like | Avoid using with alcohol

Question 44

Metronidazole mechanism

Answer 44

not sure - metabolise drug and activates it | blocks nucleic acid synthesis

Question 45

Antifungals 2 groups

Answer 45

Azoles | Polyenes

Question 46

Azoles mechanism

Answer 46

Inhibit fungal cytochrome P450 3A enzyme cant form ergosterol inhibits replication

Question 47

Azoles eg

Answer 47

Clotrimazole Ketoconazole Fluconazole

Question 48

Azole use

Answer 48

Candida infections

Question 49

Polyenes mechanism

Answer 49

doughnut hole in cell membrane leaky

Question 50

polyenes eg

Answer 50

Amphotericin (systemic fungal) | Nyastin (candida)

Question 51

Anti virals 2

Answer 51

Aciclovir (DNA polymerase inhibitors) | Oseltamivir (neuraminidase inhibitor)

Question 52

Aciclovir mechanism

Answer 52

phosphorylated by virus | inhibits DNA polymerase

Question 53

Aciclovir use

Answer 53

``` Herpes Varicella zoster (chicken pox, shingles) ```

Question 54

Oseltamivir mechanism

Answer 54

Inhibits enzyme (neuraminidase) that allows virions to bud and escape host cell enzyme usually cuts the buds off